Reviewers: Erik Corry, danno,
Description:
Do not use deprecated ARM instructions in DirectCEntryStub::GenerateCall.
Non-ancient versions of the ARM-ARM explicitly deprecate most uses of the PC
within instructions and older ARM implementations have a non-predictable
offset
(8 or 12) for some of these deprecated uses. Avoiding the deprecated
instruction
costs us one additional instruction in DirectCEntryStub::GenerateCall, but
this
should not cause any significant performance degradation.
The deoptimizer still uses the PC in a stm instruction, but it is a bit
unclear
what to do about that, so simply a comment has been added to reconsider
this in
the future.
Please review this at http://codereview.chromium.org/7633014/
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/arm/code-stubs-arm.cc
M src/arm/deoptimizer-arm.cc
Index: src/arm/code-stubs-arm.cc
===================================================================
--- src/arm/code-stubs-arm.cc (revision 8912)
+++ src/arm/code-stubs-arm.cc (working copy)
@@ -6319,7 +6319,9 @@
RelocInfo::CODE_TARGET));
__ mov(r2, Operand(function));
// Push return address (accessible to GC through exit frame pc).
- __ str(pc, MemOperand(sp, 0));
+ // Note that using pc with str is deprecated.
+ __ add(ip, pc, Operand(4));
+ __ str(ip, MemOperand(sp, 0));
__ Jump(r2); // Call the api function.
}
@@ -6329,7 +6331,9 @@
__ mov(lr, Operand(reinterpret_cast<intptr_t>(GetCode().location()),
RelocInfo::CODE_TARGET));
// Push return address (accessible to GC through exit frame pc).
- __ str(pc, MemOperand(sp, 0));
+ // Note that using pc with str is deprecated.
+ __ add(ip, pc, Operand(4));
+ __ str(ip, MemOperand(sp, 0));
__ Jump(target); // Call the C++ function.
}
Index: src/arm/deoptimizer-arm.cc
===================================================================
--- src/arm/deoptimizer-arm.cc (revision 8912)
+++ src/arm/deoptimizer-arm.cc (working copy)
@@ -593,6 +593,8 @@
__ vstm(db_w, sp, first, last);
// Push all 16 registers (needed to populate
FrameDescription::registers_).
+ // Note that using pc with stm is deprecated, so we should perhaps
handle this
+ // a bit differently.
__ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
const int kSavedRegistersAreaSize =
--
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